1. Field of Invention
The present invention relates to a gas generator for a restraining device such as an airbag system for a vehicle.
2. Description of the Related Art
In a gas generator, a solid gas-generating agent and an igniter for igniting the gas-generating agent are accommodated in a metallic housing to ensure resistance to pressure and heat during actuation. The gas generator is attached inside a module case.
The metallic housing of a conventional gas generator is connected to a metal section of the module case, and the module case is connected to a metal portion of a vehicle body.
Therefore, even when electricity (electric charges) has accumulated in the metallic housing (when the metallic housing is charged), the electric charges are discharged to the vehicle body, thereby preventing the occurrence of unwanted ignition (unpredicted ignition caused by malfunction) caused by electric discharge.
However, in recent years, a damper formed of a rubber or the like is installed between the module case and the gas generator housing, or part of the module case is formed from a resin to prevent a steering wheel from resonating with engine vibrations.
Therefore, the metallic housing of the gas generator is electrically insulated from the outside and the electric charges accumulated in the gas generator housing are not discharged, which can result in an unwanted ignition of the gas generator.
JP-A No. 2003-034217 discloses an airbag inflator. This inflator is held movably with respect to an airbag housing by an annular spring element made from a polymer material and impermeable to gas. The spring element is reliably fixed to the gas generator and module case in order to inhibit vibrations from a vehicle body.